diff --git a/GKlibSystem.cmake b/GKlibSystem.cmake
index 31a1cf1..15ccfe7 100644
--- a/GKlibSystem.cmake
+++ b/GKlibSystem.cmake
@@ -31,21 +31,6 @@ endif(CYGWIN)
 if(CMAKE_COMPILER_IS_GNUCC)
 # GCC opts.
   set(GKlib_COPTIONS "${GKlib_COPTIONS} -std=c99 -fno-strict-aliasing")
-if(VALGRIND)
-  set(GKlib_COPTIONS "${GK_COPTIONS} -march=x86-64 -mtune=generic")
-else()
-# -march=native is not a valid flag on PPC:
-if(CMAKE_SYSTEM_PROCESSOR MATCHES "power|ppc|powerpc|ppc64|powerpc64" OR (APPLE AND CMAKE_OSX_ARCHITECTURES MATCHES "ppc|ppc64"))
-  set(GKlib_COPTIONS "${GKlib_COPTIONS} -mtune=native")
-else()
-  set(GKlib_COPTIONS "${GKlib_COPTIONS} -march=native")
-endif()
-endif(VALGRIND)
-  if(NOT MINGW)
-      set(GKlib_COPTIONS "${GKlib_COPTIONS} -fPIC")
-  endif(NOT MINGW)
-# GCC warnings.
-  set(GKlib_COPTIONS "${GKlib_COPTIONS} -Werror -Wall -pedantic -Wno-unused-function -Wno-unused-but-set-variable -Wno-unused-variable -Wno-unknown-pragmas -Wno-unused-label")
 elseif(${CMAKE_C_COMPILER_ID} MATCHES "Sun")
 # Sun insists on -xc99.
   set(GKlib_COPTIONS "${GKlib_COPTIONS} -xc99")
@@ -71,24 +56,6 @@ if(NO_X86)
   set(GKlib_COPTIONS "${GKlib_COPTIONS} -DNO_X86=${NO_X86}")
 endif(NO_X86)
 
-# Add various definitions.
-if(GDB)
-  set(GKlib_COPTS "${GKlib_COPTS} -g")
-  set(GKlib_COPTIONS "${GKlib_COPTIONS} -Werror")
-else()
-  set(GKlib_COPTS "-O3")
-endif(GDB)
-
-
-if(DEBUG)
-  set(GKlib_COPTS "-g")
-  set(GKlib_COPTIONS "${GKlib_COPTIONS} -DDEBUG")
-endif(DEBUG)
-
-if(GPROF)
-  set(GKlib_COPTS "-pg")
-endif(GPROF)
-
 if(NOT ASSERT)
   set(GKlib_COPTIONS "${GKlib_COPTIONS} -DNDEBUG")
 endif(NOT ASSERT)
